.TH std::basic_string::find_first_not_of 3 "2024.06.10" "http://cppreference.com" "C++ Standard Libary"
.SH NAME
std::basic_string::find_first_not_of \- std::basic_string::find_first_not_of

.SH Synopsis
   size_type find_first_not_of( const basic_string& str,    \fB(1)\fP (noexcept since C++11)
                                size_type pos = 0 ) const;      (constexpr since C++20)
   size_type find_first_not_of( const CharT* s,
                                size_type pos, size_type    \fB(2)\fP (constexpr since C++20)
   count ) const;
   size_type find_first_not_of( const CharT* s,             \fB(3)\fP (constexpr since C++20)
                                size_type pos = 0 ) const;
   size_type find_first_not_of( CharT ch, size_type pos = 0 \fB(4)\fP (noexcept since C++11)
   ) const;                                                     (constexpr since C++20)
   template< class StringViewLike >

   size_type                                                    \fI(since C++17)\fP
       find_first_not_of( const StringViewLike& t,          \fB(5)\fP (constexpr since C++20)

                          size_type pos = 0 ) const
   noexcept(/* see below */);

   Finds the first character equal to none of the characters in the given character
   sequence. The search considers only the range [pos, size()). If all characters in
   the range can be found in the given character sequence, npos will be returned.

   1) Finds the first character equal to none of characters in str.
   2) Finds the first character equal to none of characters in range [s, s + count).
   This range can include null characters.
   If [s, s + count) is not a valid range, the behavior is undefined.
   3) Finds the first character equal to none of characters in character string pointed
   to by s. The length of the string is determined by the first null character using
   Traits::length(s).
   If [s, s + Traits::length(s)) is not a valid range, the behavior is undefined.
   4) Finds the first character not equal to ch.
   5) Implicitly converts t to a string view sv as if by std::basic_string_view<CharT,
   Traits> sv = t;, then finds the first character equal to none of characters in sv.
   This overload participates in overload resolution only if
   std::is_convertible_v<const StringViewLike&,
                         std::basic_string_view<CharT, Traits>> is true and
   std::is_convertible_v<const StringViewLike&, const CharT*> is false.

   In all cases, equality is checked by calling Traits::eq.

.SH Parameters

   str   - string identifying characters to search for
   pos   - position for the search to start from
   count - length of character string identifying characters to search for
   s     - pointer to a character string identifying characters to search for
   ch    - character identifying characters to search for
   t     - object (convertible to std::basic_string_view) identifying characters to
           search for

.SH Return value

   Position of the found character or std::string::npos if no such character is found.

.SH Exceptions

   1,4) Throws nothing.
   5)
   noexcept specification:
   noexcept(std::is_nothrow_convertible_v<const T&, std::basic_string_view<CharT,
   Traits>>)

   If an exception is thrown for any reason, this function has no effect (strong
   exception safety guarantee).

.SH Example


// Run this code

 #include <iostream>
 #include <string>

 int main()
 {
     // Permit uppercase letters, lowercase letters and numbers in macro names
     const char* pattern = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
                           "abcdefghijklmnopqrstuvwxyz"
                           "0123456789";

     std::string data = "1) %FIX, 2) %HACK, and 3) %TODO";
     const std::string replacement = "%DONE%";

     std::cout << "Before: " << data << '\\n';

     for (std::string::size_type first{}, last{};
         (first = data.find('%', first)) != std::string::npos;
         first += replacement.size())
     {
         last = data.find_first_not_of(pattern, first + 1);
         if (last == std::string::npos)
             last = data.length();

         // Now first at '%' and last is one past end of the found substring
         data.replace(first, last - first, replacement);
     }

     std::cout << "After: " << data << '\\n';
 }

.SH Output:

 Before: 1) %FIX, 2) %HACK, and 3) %TODO
 After: 1) %DONE%, 2) %DONE%, and 3) %DONE%

   Defect reports

   The following behavior-changing defect reports were applied retroactively to
   previously published C++ standards.

      DR    Applied to           Behavior as published              Correct behavior
   LWG 847  C++98      there was no exception safety guarantee   added strong exception
                                                                 safety guarantee
   LWG 2064 C++11      overloads (3,4) were noexcept             removed
   LWG 2946 C++17      overload \fB(5)\fP caused ambiguity in some     avoided by making it a
                       cases                                     template
   P1148R0  C++11      noexcept for overloads (4,5) were         restored
            C++17      accidentally dropped by LWG2064/LWG2946

.SH See also

   find              finds the first occurrence of the given substring
                     \fI(public member function)\fP
   rfind             find the last occurrence of a substring
                     \fI(public member function)\fP
   find_first_of     find first occurrence of characters
                     \fI(public member function)\fP
   find_last_of      find last occurrence of characters
                     \fI(public member function)\fP
   find_last_not_of  find last absence of characters
                     \fI(public member function)\fP
                     find first absence of characters
   find_first_not_of \fI(public member function of std::basic_string_view<CharT,Traits>)\fP


.SH Category:
     * conditionally noexcept
